We explore the relevance of confinement in quark matter models for the possible quark core of neutron stars. For the quark phase, we adopt the equation of state (EoS) derived with the Field Correlator Method, extended to the zero temperature limit. For the hadronic phase, we use the microscopic Brueckner-Hartree-Fock many-body theory. We find that the currently adopted value of the gluon condensate $G_2 \simeq 0.006-0.007 \rm {GeV^4}$, which gives a critical temperature $T_c \simeq 170 \rm MeV$, produces maximum masses which are only marginally consistent with the observational limit, while larger masses are possible if the gluon condensate is increased.
We generalize a recently proposed confining relativistic density-functional approach to the case of density dependent vector and diquark couplings. The particular behavior of these couplings is motivated by the non-perturbative gluon exchange in dense quark matter and provides the conformal limit at asymptotically high densities. We demonstrate that this feature of the quark matter EoS is consistent with a significant stiffness in the density range typical for the interiors of neutron stars. In order to model these astrophysical objects we construct a family of hybrid quark-hadron EoSs of cold…
Study of the Emergence of a Gluon Mass Scale from Center Vortices Using a Wave-Functional Formalism
Universidade Estadual Paulista（圣保罗州立大学）；South-American Institute of Fundamental Research ICTP-SAIFR（南美基础研究所 ICTP-SAIFR）；Universität Tübingen（蒂宾根大学）；Universidade Federal Fluminense（弗鲁米嫩塞联邦大学）
We evaluate the longitudinal or (chromo-)electric Yang-Mills gluon propagator in the recently proposed center-symmetric Landau gauge at finite temperature [1]. To model the effect of the Gribov copies in the infrared, we use the Curci-Ferrari model which, in turn, allows us to rely on perturbative calculations. At one-loop order in the SU(2) case, the so-obtained longitudinal gluon propagator provides a clear signature for Z2 center-symmetry breaking with a singular behavior, characteristic of a continuous phase transition. This is in sharp contrast with what is found within the standard Landa…
Above the pseudocritical temperature T_c of chiral symmetry restoration a chiral spin symmetry (a symmetry of the color charge and of electric confinement) emerges in QCD. This implies that QCD is in a confining mode and there are no free quarks. At the same time correlators of operators constrained by a conserved current behave as if quarks were free. This explains observed fluctuations of conserved charges and the absence of the rho-like structures seen via dileptons. An independent evidence that one is in a confining mode is very welcome. Here we suggest a new tool how to distinguish free q…
Fluctuations of conserved charges such as baryon number, electric charge and strangeness may provide a test for completeness of states in lattice QCD for three light flavors. We elaborate on the idea that the corresponding susceptibilities can be saturated with excited baryonic states with an underlying quark-diquark structure with a linearly confining interaction. Using Polyakov-loop correlators we show that in the static limit, the quark-diquark potential coincides with the quark-antiquark potential in marked agreement with recent lattice studies. We thus study in a quark-diquark model the b…
High-mass twins & resolution of the reconfinement, masquerade and hyperon puzzles of compact star interiors
我们的目标是有助于解决与致密星致密核结构（CS）有关的三个基本难题：（i）超子难题：如何协调$2\,$ M $_\odot$的脉冲星质量与超子软化状态方程（EoS）;（ii）伪装问题：现代EOS冷，高密度强子和夸克物质几乎是相同的;（iii）的refinement难题：怎么办时，解除禁闭过渡后的强子EOS再次成为有利的？我们表明，考虑到重子的复合性（排除体积和/或夸克泡利阻塞）的强子侧和夸克物质侧的限制和硬化效应的结果在早期的相变到夸克物质，在高密度，消除了所有三个目前的CS内部的困惑。此外，在这类新的EoS的混合CS下降的一个有趣的情况下，一个强的一阶相变，导致可观察到的高质量的双星现象，天体物理观测的一个关键端点的QCD相图。
